The fundamental purpose of the Data and Methods Core is to facilitate integration of the component projects in the Center and promote their synergy. The Core will also promote efficiency and economy in the work of the Center. The Core will have four specific aims: 1. To develop and maintain an efficient, cost-effective, and state-of-the-art computing environment for individual research projects by evaluating promising new software, advising research staff on desirable computing configurations, and providing intermittently used, fixed-cost hardware resources. 2. To create, document, update, and disseminate a library of contextual data on neighborhoods and neighborhood characteristics as well as other data relevant to research regarding the impact of neighborhoods on health. Such data will be common to several projects, and are often prohibitively expensive to collect for individual projects. 3. To provide a locus for communication and intellectual exchange among the project leaders and other investigators regarding the conceptualization of neighborhoods and their features, including neighborhood definitions and measures for characterizing neighborhoods and their impact on health. 4. To provide a locus for sharing information about and developing common approaches to construction of measures and empirical estimation problems. The Core will achieve these aims in three ways: by providing the computing infrastructure to address common computing needs of all the component projects, by providing the locus for intellectual exchange regarding conceptual and empirical issues in the study of neighborhood effects on health, and by serving as a repository of contextual data on neighborhoods that will be used by multiple projects. The staffing plan for the Core will include a Core director and co-director, Core investigators and statisticians, two programmers and a project manager. Meetings of Core staff and project investigators will enhance the quality of the core's work and foster collaboration and integration.